tpjj. Analyfts of the Air. 
and abforbed by animal, vegetable and mi- 
neral fubfrances. 
That this air confifts of particles which are 
in a very active ftate, repelling each other 
with force, and thereby conftituting the fame 
kind of elaftick fluid with common air, is 
plain from its railing the Mercury in Expe- 
riment 8 s and 89, and from its continu- 
ing in that elaftick ftate for many months 
and years tho* cooled by fevere frofts 5 where- 
as watry vapours, tho' they expand much 
with heat, yet are found immediately to con- 
denfe into their firfl: dimenfions when cold? 
The air generated by fire was not, in 
many inftanccs, feparated without great vio- 
lence from the fix’d bodies, in which it 
was incorporated 3 as in the cafe of Nitre , 
Tartar^ $alTartar&vi<\ Copperas: whence it 
Should feem, that the air generated from 
thefe Saits, may probably be very inftru- 
mentalin the union of Salts, as well as that 
central, denfer, and comparer particle of 
earth, which Sir Ifaac Newton obferves, 
does by its attraction make the watry acid 
flow round it, for compoling the particles of 
Salt. qu. 3 1. For fince upon the diffolution 
pf the conftituent parts of Salt by fire, it is 
found, that upon feparatipg and volatilizing 
